scholarly journals Systematizing the effective theory of self-interacting dark matter

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Prateek Agrawal ◽  
Aditya Parikh ◽  
Matthew Reece
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Axial Vector ◽  
Effective Theory ◽  
Tree Level ◽  
Low Velocity ◽  
Scattering Rate ◽  
Light Scalar ◽  
Sommerfeld Enhancement ◽  
Particle Nature

Abstract If dark matter has strong self-interactions, future astrophysical and cosmological observations, together with a clearer understanding of baryonic feedback effects, might be used to extract the velocity dependence of the dark matter scattering rate. To interpret such data, we should understand what predictions for this quantity are made by various models of the underlying particle nature of dark matter. In this paper, we systematically compute this function for fermionic dark matter with light bosonic mediators of vector, scalar, axial vector, and pseudoscalar type. We do this by matching to the nonrelativistic effective theory of self-interacting dark matter and then computing the spin-averaged viscosity cross section nonperturbatively by solving the Schrödinger equation, thus accounting for any possible Sommerfeld enhancement of the low-velocity cross section. In the pseudoscalar case, this requires a coupled-channel analysis of different angular momentum modes. We find, contrary to some earlier analyses, that nonrelativistic effects only provide a significant enhancement for the cases of light scalar and vector mediators. Scattering from light pseudoscalar and axial vector mediators is well described by tree-level quantum field theory.

scholarly journals Electroweak corrections in a pseudo Nambu-Goldstone Dark Matter model revisited

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Seraina Glaus ◽  
Margarete Mühlleitner ◽  
Jonas Müller ◽  
Shruti Patel ◽  
Tizian Römer ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Parameter Space ◽  
Goldstone Boson ◽  
Indirect Evidence ◽  
Tree Level ◽  
Dark Matter Candidate ◽  
Nucleon Scattering ◽  
The Cross ◽  
Electroweak Corrections

Abstract Having so far only indirect evidence for the existence of Dark Matter a plethora of experiments aims at direct detection of Dark Matter through the scattering of Dark Matter particles off atomic nuclei. For the correct interpretation and identification of the underlying nature of the Dark Matter constituents higher-order corrections to the cross section of Dark Matter-nucleon scattering are important, in particular in models where the tree-level cross section is negligibly small. In this work we revisit the electroweak corrections to the dark matter-nucleon scattering cross section in a model with a pseudo Nambu-Goldstone boson as the Dark Matter candidate. Two calculations that already exist in the literature, apply different approaches resulting in different final results for the cross section in some regions of the parameter space leading us to redo the calculation and analyse the two approaches to clarify the situation. We furthermore update the experimental constraints and examine the regions of the parameter space where the cross section is above the neutrino floor but which can only be probed in the far future.

scholarly journals Analogies between nuclear physics and dark matter

2014 ◽  
Vol 29 (39) ◽  
pp. 1450209 ◽  
Author(s):  
D. Cárcamo ◽  
A. Riveros ◽  
J. Gamboa
Keyword(s):  
Dark Matter ◽  
Cross Sections ◽  
Nuclear Physics ◽  
Tree Level ◽  
Total Cross Sections ◽  
Sommerfeld Enhancement ◽  
Body Potential

A fermionic description of dark matter using analogies with nuclear physics is developed. At tree level, scalar and vector processes are considered and the two-body potential are explicitly calculated using the Breit approximation. We show that the total cross-sections in both cases exhibit Sommerfeld enhancement.

scholarly journals Dark matter in minimal dimensional transmutation with multicritical-point principle

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Yuta Hamada ◽  
Hikaru Kawai ◽  
Kin-ya Oda ◽  
Kei Yagyu
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Scale Invariance ◽  
Direct Detection ◽  
Planck Scale ◽  
Higgs Field ◽  
Scalar Fields ◽  
Tree Level ◽  
Multicritical Point ◽  
Dimensional Transmutation

Abstract We investigate a model with two real scalar fields that minimally generates exponentially different scales in an analog of the Coleman-Weinberg mechanism. The classical scale invariance — the absence of dimensionful parameters in the tree-level action, required in such a scale generation — can naturally be understood as a special case of the multicritical-point principle. This two-scalar model can couple to the Standard Model Higgs field to realize a maximum multicriticality (with all the dimensionful parameters being tuned to critical values) for field values around the electroweak scale, providing a generalization of the classical scale invariance to a wider class of criticality. As a bonus, one of the two scalars can be identified as Higgs-portal dark matter. We find that this model can be consistent with the constraints from dark matter relic abundance, its direct detection experiments, and the latest LHC data, while keeping the perturbativity up to the reduced Planck scale. We then present successful benchmark points satisfying all these constraints: the mass of dark matter is a few TeV, and its scattering cross section with nuclei is of the order of 10−9 pb, reachable in near future experiments. The mass of extra Higgs boson H is smaller than or of the order of 100 GeV, and the cross section of e+e− → ZH can be of fb level for collision energy 250 GeV, targetted at future lepton colliders.

scholarly journals The Fermi–LAT Galactic Center Excess: Evidence of Annihilating Dark Matter?

2020 ◽  
Vol 70 (1) ◽  
pp. 455-483
Author(s):  
Simona Murgia
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Galactic Center ◽  
Dark Matter Particle ◽  
Point Sources ◽  
Current Status ◽  
Large Area ◽  
200 Gev ◽  
Γ Rays ◽  
Particle Nature

The center of the Galaxy is one of the prime targets in the search for a signal of annihilating (or decaying) dark matter. If such a signal were to be detected, it would shed light on one of the biggest mysteries in physics today: What is dark matter? Fundamental properties of the particle nature of dark matter, such as its mass, annihilation cross section, and annihilation final states, could be measured for the first time. Several experiments have searched for such a signal, and some have measured excesses that are compatible with it. A long-standing and compelling excess is observed in γ-rays by the Fermi Large Area Telescope ( Fermi–LAT). This excess is consistent with a dark matter particle with a mass of approximately 50 (up to ∼200) GeV annihilating with a velocity-averaged cross section of ∼10−26 cm3 s−1. Although a dark matter origin of the excess remains viable, other interpretations are possible. In particular, there is some evidence that the excess is produced by a population of unresolved point sources of γ-rays—for example, millisecond pulsars. In this article, I review the current status of the observation of the Fermi–LAT Galactic center excess, the possible interpretations of the excess, the evidence and counterevidence for each, and the prospects for resolving its origin with future measurements.

SCALAR TOP PRODUCTION VIA BOSON-GLUON FUSION AT HERA

1992 ◽  
Vol 07 (14) ◽  
pp. 1209-1218 ◽  
Author(s):  
TETSURO KOBAYASHI ◽  
TADASHI KON ◽  
KEIICHIRO NAKAMURA ◽  
TAKESHI SUZUKI
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Top Quark ◽  
Gluon Fusion ◽  
Top Quarks ◽  
Tree Level ◽  
Mixing Angle ◽  
Light Scalar ◽  
Scalar Top ◽  
Level Calculation

We investigate the production of the light scalar top quark [Formula: see text] via boson-gluon fusion at ep collider HERA, based on the minimal supersymmetric standard model. The cross-section is obtained by both an exact tree level calculation and the Weizsäcker-Williams approximation. It is shown that the total cross-section is larger than 0.1pb if [Formula: see text] and does not depend on the mixing angle θt of scalar top quarks. This enables us to search a possible region of parameters for existence of light scalar top at HERA in a wider parameter space [Formula: see text] than LEP.

scholarly journals Closing the window on WIMP Dark Matter

2022 ◽  
Vol 82 (1) ◽  
Author(s):  
Salvatore Bottaro ◽  
Dario Buttazzo ◽  
Marco Costa ◽  
Roberto Franceschini ◽  
Paolo Panci ◽  
...  
Keyword(s):  
Dark Matter ◽  
Gauge Boson ◽  
Bound States ◽  
Direct Detection ◽  
High Energy ◽  
Tree Level ◽  
Boson Exchange ◽  
Future Collider ◽  
Sommerfeld Enhancement ◽  
The Masses

AbstractWe study scenarios where Dark Matter is a weakly interacting particle (WIMP) embedded in an ElectroWeak multiplet. In particular, we consider real SU(2) representations with zero hypercharge, that automatically avoid direct detection constraints from tree-level Z-exchange. We compute for the first time all the calculable thermal masses for scalar and fermionic WIMPs, including Sommerfeld enhancement and bound states formation at leading order in gauge boson exchange and emission. WIMP masses of few hundred TeV are shown to be compatible both with s-wave unitarity of the annihilation cross-section, and perturbativity. We also provide theory uncertainties on the masses for all multiplets, which are shown to be significant for large SU(2) multiplets. We then outline a strategy to probe these scenarios at future experiments. Electroweak 3-plets and 5-plets have masses up to about 16 TeV and can efficiently be probed at a high energy muon collider. We study various experimental signatures, such as single and double gauge boson emission with missing energy, and disappearing tracks, and determine the collider energy and luminosity required to probe the thermal Dark Matter masses. Larger multiplets are out of reach of any realistic future collider, but can be tested in future $$\gamma $$ γ -ray telescopes and possibly in large-exposure liquid Xenon experiments.

Possibility of hadronic dark matter

2019 ◽  
Vol 28 (13) ◽  
pp. 1941001 ◽  
Author(s):  
Vitaly Beylin ◽  
Vladimir Kuksa
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Cross Section ◽  
Low Energy ◽  
Annihilation Cross Section ◽  
Strong Interactions ◽  
Charged State ◽  
Energy Potential ◽  
The Standard Model ◽  
Sommerfeld Enhancement

We consider main properties of hadronic Dark Matter (DM) candidate consisting of new heavy stable quark and the light ordinary one. This additional quark arises in chiral-symmetric extension of the Standard Model and has standard electromagnetic and strong interactions. Neutral and charged pseudoscalar low-lying states are interpreted as the DM carrier and its nearest charged partner. Their masses and lifetime of the charged state are evaluated; we also describe asymptotics of low-energy potential of the particles interactions with nucleons and each other. Annihilation cross-section is calculated and some peculiarities of Sommerfeld enhancement are analyzed.

scholarly journals Stochastic Inflation at NNLO

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Timothy Cohen ◽  
Daniel Green ◽  
Akhil Premkumar ◽  
Alexander Ridgway
Keyword(s):  
Renormalization Group ◽  
Initial Conditions ◽  
Planck Equation ◽  
Effective Theory ◽  
Tree Level ◽  
Order Effects ◽  
De Sitter ◽  
Light Scalar ◽  
Non Gaussian ◽  
Group Flow

Abstract Stochastic Inflation is an important framework for understanding the physics of de Sitter space and the phenomenology of inflation. In the leading approximation, this approach results in a Fokker-Planck equation that calculates the probability distribution for a light scalar field as a function of time. Despite its successes, the quantum field theoretic origins and the range of validity for this equation have remained elusive, and establishing a formalism to systematically incorporate higher order effects has been an area of active study. In this paper, we calculate the next-to-next-to-leading order (NNLO) corrections to Stochastic Inflation using Soft de Sitter Effective Theory (SdSET). In this effective description, Stochastic Inflation manifests as the renormalization group evolution of composite operators. The leading impact of non-Gaussian quantum fluctuations appears at NNLO, which is presented here for the first time; we derive the coefficient of this term from a two-loop anomalous dimension calculation within SdSET. We solve the resulting equation to determine the NNLO equilibrium distribution and the low-lying relaxation eigenvalues. In the process, we must match the UV theory onto SdSET at one-loop order, which provides a non-trivial confirmation that the separation into Wilson-coefficient corrections and contributions to initial conditions persists beyond tree level. Furthermore, these results illustrate how the naive factorization of time and momentum integrals in SdSET no longer holds in the presence of logarithmic divergences. It is these effects that ultimately give rise to the renormalization group flow that yields Stochastic Inflation.

scholarly journals Spin-one dark matter and gamma ray signals from the galactic center

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
H. Hernández-Arellano ◽  
M. Napsuciale ◽  
S. Rodríguez
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Gamma Ray ◽  
Galactic Center ◽  
Photon Emission ◽  
Scalar Coupling ◽  
Initial State ◽  
Internal Bremsstrahlung ◽  
Resonance Effects ◽  
State Radiation

Abstract In this work we study the possibility that the gamma ray excess (GRE) at the Milky Way galactic center come from the annihilation of dark matter with a (1, 0) ⊕ (0, 1) space-time structure (spin-one dark matter, SODM). We calculate the production of prompt photons from initial state radiation, internal bremsstrahlung, final state radiation including the emission from the decay products of the μ, τ or hadronization of quarks. Next we study the delayed photon emission from the inverse Compton scattering (ICS) of electrons (produced directly or in the prompt decay of μ, τ leptons or in the hadronization of quarks produced in the annihilation of SODM) with the cosmic microwave background or starlight. All these mechanisms yield significant contributions only for Higgs resonant exchange, i.e. for M ≈ MH /2, and the results depend on the Higgs scalar coupling to SODM, gs. The dominant mechanism at the GRE bump is the prompt photon production in the hadronization of b quarks produced in $$ \overline{D}D\to \overline{b}b $$ D ¯ D → b ¯ b , whereas the delayed photon emission from the ICS of electrons coming from the hadronization of b quarks produced in the same reaction dominates at low energies (ω < 0.3 GeV ) and prompt photons from c and τ , as well as from internal bremsstrahlung, yield competitive contributions at the end point of the spectrum (ω ≥ 30 GeV ). Taking into account all these contributions, our results for photons produced in the annihilation of SODM are in good agreement with the GRE data for gs ∈ [0.98, 1.01] × 10−3 and M ∈ [62.470, 62.505] GeV . We study the consistency of the corresponding results for the dark matter relic density, the spin-independent dark matter-nucleon cross-section σp and the cross section for the annihilation of dark matter into $$ \overline{b}b $$ b ¯ b , τ+τ−, μ+μ− and γγ, taking into account the Higgs resonance effects, finding consistent results in all cases.

scholarly journals Search for dark matter in association with an energetic photon in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Dark Matter ◽  
Transverse Momentum ◽  
Standard Model ◽  
Confidence Level ◽  
Axial Vector ◽  
Beyond The Standard Model ◽  
Proton Proton ◽  
Missing Transverse Momentum ◽  
Upper Limits ◽  
The Standard Model

Abstract A search for dark matter is conducted in final states containing a photon and missing transverse momentum in proton-proton collisions at $$ \sqrt{s} $$ s = 13 TeV. The data, collected during 2015–2018 by the ATLAS experiment at the CERN LHC, correspond to an integrated luminosity of 139 fb−1. No deviations from the predictions of the Standard Model are observed and 95% confidence-level upper limits between 2.45 fb and 0.5 fb are set on the visible cross section for contributions from physics beyond the Standard Model, in different ranges of the missing transverse momentum. The results are interpreted as 95% confidence-level limits in models where weakly interacting dark-matter candidates are pair-produced via an s-channel axial-vector or vector mediator. Dark-matter candidates with masses up to 415 (580) GeV are excluded for axial-vector (vector) mediators, while the maximum excluded mass of the mediator is 1460 (1470) GeV. In addition, the results are expressed in terms of 95% confidence-level limits on the parameters of a model with an axion-like particle produced in association with a photon, and are used to constrain the coupling gaZγ of an axion-like particle to the electroweak gauge bosons.

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